Lucilia Robineau-Desvoidy

Species descriptions Tables 1 and 2 provide a comparison of important morphological characters for all 23 species.

Diagnosis. The genus can be distinguished by a bare stem vein above; presence of a sclerite on the suprasquamal ridge with a conspicuous cluster of setae near the base of the scutellum and the lower calypter bare above (Whitworth 2006, fig. 14). It also normally has a metallic, shining body color. Other families (Muscidae, Sarcophagidae, and Tachinidae) have species with shining body color which may be encountered in the region, see the key to families in Whitworth (2006: 693) and the discussion in Vargas & Wood (2010) to distinguish them.

Bufolucilia Townsend, 1919 b: 542. Type species: Lucilia bufonivora Moniez, 1876, by original designation. Francilia Shannon, 1924: 74. Type species: Francilia alaskensis Shannon, 1924, by monotypy. Viridinsula Shannon, 1926: 131 (as a subgenus of Lucilia Robineau-Desvoidy, 1830). Type species: Musca pionia Walker, 1849, by original designation. Shannon (1926) erected the subgenus Viridinsula for L. pionia based on the anteroventral expansion of the head seen in male specimens. Curran (1934 b) elevated Shannon’s subgenus to full genus level for both L. pionia and L. deceptor. James (1966) concluded Curran’s elevation of Viridinsula to full genus status was not warranted and retained it as a subgenus and applied it to all three species endemic to the Galápagos. Rognes (1991) did not recognize subgenera and listed Viridinsula as a synonym of Lucilia.

Discussion. This study provides a key to the 23 Lucilia species known to occur in the Neotropical Region. See Tables 1 and 2 for a comparison of important character states used to identify these species. Twelve species were selected for detailed study, including six new species. The five species of Lucilia endemic to the West Indies, and L. cluvia will not be discussed in detail herein because they were addressed in Whitworth (2010). Three species, L. deceptor, L. pionia (Walker), and L. setosa (James) are found in the Ecuadorean Galápagos Islands. Lucilia deceptor is also found in the Costa Rican Cocos Islands. James (1966) provided descriptions and figures of male genitalia for each of these species, but they were not studied in detail. Tantawi & Sinclair (2013) conducted a more detailed study of the Galápagos species providing illustrations of male genitalia and frons of both sexes. The cosmopolitan species L. cuprina and L. sericata are also not detailed herein since they have been described by numerous authors (Hall 1948, Whitworth 2006). The Nearctic species L. coeruleiviridis Macquart, L. illustris (Meigen), and L. silvarum (Meigen) which likely occur in Mexico (James 1970) are not included in this key; these species may be keyed using Whitworth (2006: 718). Lucilia coeruleiviridis was listed as a species found in the Neotropical Region by Whitworth (2010) following Townsend (1908) who recorded it from Cuba (as L. oculata). Whitworth (2010) listed L. coeruleiviridis in Guatemala, based on a single specimen examined. The listing by Kosmann et al. (2013) of this species in the Neotropical Region appears to be based on Whitworth (2010). Since that study, the Guatemala specimen was re-examined and it was determined to be a discolored and nontypical specimen of L. eximia. Lucilia coeruleiviridis has been excluded from the key since I have not found it in the Neotropical Region and I have been unable to verify its presence in Cuba. A search of Townsend material in USNM revealed no paratypes of L. oculata, and no USNM specimens of L. coeruleiviridis from Cuba were found (Norman Woodley, pers. comm.). The record of L. oculata, and hence L. coeruleiviridis, from Cuba is assumed to have been based on a misidentified specimen. Lucilia coeruleiviridis can be determined using the key to Lucilia in Whitworth (2006) if its presence is suspected. However, it is included in the barcode diagram to show its relationship to other Lucilia (Fig. 161). Despite the paucity of good distinguishing characters in Neotropical Lucilia, this study has revealed six new species, which are described herein. The status of three species, L. japuhybensis, L. ochricornis, and L. purpurascens has been clarified herein. Head Characters. The ratio of frons to head width measured at the narrowest area of the frons is a useful character to help separate many species, especially for males. Six species have males with exceptionally broad frons (0.115 – 0.23); four have frons of medium width (0.05 – 0.06) and thirteen have narrow frons (0.01 – 0.04) (Table 1). In the species studied, the female frons is always wider than the male (0.21 – 0.39) frons; widths in females tend to be less distinctive than in males, but can be useful to help separate some species (Table 1). Seven species have some pale setae on the gena along with dark setae (as in Fig. 1). When pale setae are present on the gena, they may be limited to the posterodorsal corner of the gena or extend forward and downward to cover almost all of the gena. Species with this character state include L. albofusca, L. cluvia, L. deceptor, L. nitida, L. pulverulenta, L. rica and L. rognesi, while the remaining 16 species have only dark setae on the gena (as in Fig. 2). Occasional specimens in the group with dark seta on the gena may have a few pale setae that occur just above the junction of the postgena with the gena; specimens with this condition should still be considered to have dark setae on the gena. Fourteen species have pale, weak setae below and behind the postocular row (as in Fig. 3), eight species have stout dark setae, the condition of these setae in L. problematica was not determined (Table 1). Some species with weak setae, behind the postocular row, like L. eximia, and L. woodi, have a few stout dark setae behind the posteroventral corner of the eye, but the setae behind the rest of the postocular row are weak. These specimens are considered to have weak setae below and behind the postocular row of setae. Eye facet size was measured in 11 selected species to help separate poorly known species. See the methods section for an explanation of how facet diameters were measured. See Table 1, for a comparison of facet size by species and sex. Males of six species have anterior facets that are relatively large, ranging from 0.55 mm – 0.68 mm (as in Fig. 6). Males of the remaining five species studied have smaller anterior facets ranging from 0.40 mm – 0.49 mm (as in Fig. 5). Anterior facets in L. woodi are twice the size of posterior facets in both sexes. In L. purpurascens the anterior facets in males are twice the diameter of the posterior facets (0.64 mm / 0.32 mm) (Fig. 6), while in females the anterior and posterior facets are much smaller and more similar in size (0.45 mm / 0.34 mm). Thorax and Abdomen Characters. Chaetotaxy patterns on the thorax are similar in most species of Neotropical Lucilia, and this character is not mentioned unless the pattern varies. Exceptions are two cosmopolitan species of Lucilia, L. cuprina and L. sericata, which have three postsutural acrostichal setae, while the remaining 21 species have two postsutural acrostichals. In the Galápagos species L. deceptor, the presutural intra-alar is sometimes much reduced or absent, while it is usually stronger in all other species. Color of upper and lower calypter disc and rim are also important characters that vary with species and in some cases, by sex. Some species have upper and lower calypters pale in both sexes, L. cluvia, L. cuprina, L. deceptor, L. pionia, L. sericata, L. setosa, in others, calypters are pale except lower calypter faintly tan to brown in males only, L. eximia, L. ibis, L. mexicana, L. rica, L. ochricornis, and L. retroversa to both upper and lower calypters dark in both sexes, L. fayeae, L. nitida, L. pulverulenta, L. purpurascens, L. vulgata, L. woodi, L. japuhybensis, L. rognesi (Fig. 8), to upper and lower dark in males and upper pale and lower dark in females, L. problematica, to upper calypter pale and lower dark in both sexes, L. albofusca (Fig. 9), L. lucigerens. Basicosta color is dark brown to tan in most species (Fig. 11); only L. cluvia, L. cuprina, L. deceptor, L. problematica, L. retroversa and L. sericata have whitish to orange colored basicostas (Fig. 10). The presence or absence of the coxopleural streak can help distinguish species (Table 2). When present, it is a suture-like depression between the katepimeron and meron (see Rognes 1991, fig. 6 or Whitworth 2006, fig. 16). The streak is often paler in color and distinct, when there is no color difference, the suture can be hard to see. On the mainland of Central and South America, species with pale setae on the gena lack the streak, except it is present in L. cluvia, which occurs in Central America. In the Galápagos, Cocos and West Indies islands, L. deceptor (Galápagos and Cocos) has pale setae and lacks the streak, while L. rica (West Indies) has both pale setae and the streak. Again on the mainland, all species with dark setae on the gena have the streak present, except L. purpurascens and L. woodi. The island species of L. pionia and L. setosa (Galápagos) and L. retroversa (West Indies) have dark setae on the gena, and lack the streak; in L. fayeae (West Indies) the streak is variable, it is distinct in some specimens and absent in others. Microtomentum patterns on the thorax and abdomen provide useful characters; see Table 2 for a comparison between species. The thorax may be covered with microtomentum (as in Fig. 12), limited to the presutural area (as in Fig. 13), small patches (as in Fig. 14) or the whole thorax may be polished (as in Fig. 15). In most species, the abdomen has T 1 + 2 dark greenish or bluish black T 1 + 2 and T 3 usually have microtomentum, while some or all of segments T 4 and T 5 are polished. The posterior edges of T 3 and T 4 have black bands in the three endemic Galápagos species. Faint bands can sometimes be seen in the same area on other Lucilia species. Generally body color cannot be relied on for species distinctions, with a few exceptions. Two Neotropical species lack the bright, shining body color, the West Indies L. problematica, and the Galápagos and Cocos Islands L. deceptor (Curran) are dull colored with dense microtomentum and only faint underlying metallic blackish-green color. For L. ibis, the very distinctive violet-pink body color is a useful character (Fig. 21), as is the bright aeneous coloration on T 5 in most L. lucigerens. Males. Frons width in males tends to be very consistent within species and is an important key character for many species. See Table 1 for a comparison of frons to head ratios for each species. The shape of surstyli and cerci tends to be very similar between species, but in lateral view, they fall into a few more or less distinct groups: surstylus short broad, parallel sided (digitate), L. cuprina (Hall 1948, figs. K, L), L. ibis, L. ochricornis, L. sericata (Hall 1948, figs. F, G), L. vulgata (Figs. 43, 44; 51, 52, 59, 60 respectively); surstylus a little longer, narrower, parallel sided, L. woodi (Fig. 61, 62); surstylus medium length, digitate, gradually expanded toward distal end of surstylus, L. nitida (Fig. 49, 50); surstylus medium length, curved forward with distal end expanded, L. purpurascens (Figs. 55, 56), L. lucigerens (Whitworth 2010, figs. 46, 47), L. retroversa (Whitworth 2010, figs. 48, 49); surstylus medium length, parallel sided, L. albofusca (Figs. 39, 40), L. problematica (Hall 1948, p. 423, A, B), L. pulverulenta (Figs. 53, 54), L. rica (Whitworth 2010, figs. 50, 51), L. rognesi (Figs. 57, 58); surstylus with distal end narrower, and curved slightly forward, L. cluvia (figs. 38, 39, Whitworth 2010), L. eximia (Figs. 41, 42), L. pionia (James 1966, fig. 2; Tantawi & Sinclair 2013, figs. 3 G, H); surstylus medium length, narrower at base, distal half expanded, L. fayeae (Whitworth 2010, figs. 44, 45); surstylus in lateral view medium length, slightly curved forward, slender and parallel sided; in posterior view the cerci and surstyli are about equal in length, L. setosa (James 1966, figs. 7, 8; Tantawi & Sinclair 2013, figs. 2 E, F); surstylus longer, slender, curved forward, parallel sided, L. mexicana (Figs. 47, 48) and L. japuhybensis (Figs. 45, 46). Lucilia mexicana also has distinctive upside down Y-shaped cerci in the posterior view, and tip of cercus with distinct hook (Figs. 47, 48). Lucilia japuhybensis surstyli and cerci are exceptionally long, and in lateral view, the tip of the cercus is hooked like L. mexicana. Lucilia deceptor cerci are long and slender, much longer than surstyli; tips of cerci diverge in posterior view, in lateral view, the tip of the surstylus is enlarged and extends posteriorly (James 1966 figs. 4, 5; Tantawi & Sinclair 2013, figs 1 E, F. Phalli of the 12 species studied in detail herein (Figs. 63 – 86) are very similar to those illustrated in Whitworth (2010), figs. 52 – 63. The epiphallus is broad and cupped and the distal end curves forward, tip angling more or less sharply downward. The epiphallus originates near posterior end of basiphallus in most species; it is slightly farther forward in L. mexicana and L. japuhybensis. The venter of hypophallus is serrated; tip of paraphallus curves down and usually slightly to the rear; acrophallus similar in all species, anterior end with posterior pointing denticles. Shape of hypandria is more or less distinctive in each species although variation is minimal between species; width of distal end tends to be narrower in species such as L. japuhybensis and L. woodi, while broader in species like L. mexicana, L. ochricornis, L. purpurascens, and L. vulgata. The pre- and postgonites of all species are similar, the pregonite has 3 – 4 setae, including one on the tip, while the postgonite has a single long seta originating from near the base. The ejaculatory sclerites are similar, broader in L. mexicana and L. nitida, while narrower in the remaining species. See Figs. 87 – 122 for photos of hypandria, pre- and postgonites, and ejaculatory sclerites. The sternites are also similar, though the exact shape and size of each sternite varies between species, especially in segments ST 2 and ST 4 – 5 (Figs. 123 – 134). Females. Females share many characters with males, but they consistently differ in several ways. In the 23 species studied, frons width was broader than males, (0.21 – 0.39 of head width at narrowest) (see Table 1 for a comparison of species), with one lateroclinate and two proclinate orbital setae. Typically the frontal vitta and fronto-orbitals are much broader in females than males and the frontal setae extend the full length of the frontoorbital plate, while in most males, they do not. Normally the pattern of microtomentum on the thorax does not vary significantly between sexes, but in some species the pattern on the abdomen may vary. If it is significant, it is mentioned in the species discussion. The most extreme example is in L. mexicana where females have all but the front edge of T 5 polished, while in males, only the rear half of T 5 is polished. For some species, calypter color of the upper and lower calypters differs between sexes (Table 2). See Whitworth (2010) for a discussion of ovipositor characters of four species endemic to the West Indies, and L. cluvia. Lucilia problematica females were not dissected. The female genitalia of Galápagos species L. deceptor, L. pionia, and L. setosa also were not dissected in this study and their condition is unknown. In the 12 species studied in detail, female genitalia were dissected and ovipositors and spermathecae were illustrated (Figs. 135 – 158). Tergites and sternites 6 – 8 of the ovipositor exhibited some variation between species. In 9 species, the cuticle on the anterior margin of T 6 is weakened and translucent, in 2 species, L. mexicana and L. rognesi, only the anterolateral corners are weakened, and in one species, L. eximia, there is no weakening. ST 6 of most species have lateral margins weakened and ST 6 – 7 has a posterior digit-like prolongation into the intersegmental membrane. This digit-like extension is found in 11 of the 12 species studied herein; only L. purpurascens lacks these extensions (Fig. 143). When the ovipositors of West Indies Lucilia were studied (Whitworth 2010) these structures were not noted, but upon re-examination the projections are present to some degree in all. Rognes (1991) also found these extensions in some species of Lucilia he studied in Fennoscandia and Denmark. The central portion of T 7 is at least partially divided by weakened, translucent cuticle and / or membrane in all 12 species. The pattern of cuticular weakening extends the full length of the tergite in L. eximia, L. ibis, L. ochricornis, L. nitida, L. purpurascens, and L. woodi; in the remaining species the division of the tergite ends just short of the posterior margin. The weakened cuticle is further separated by membrane in all species, ranging from a tiny area of membrane at the anterior edge in L. ochricornis to the anterior two-thirds of the segment in L. albofusca, L. eximia, L. nitida, L. purpurascens, L. rognesi, L. vulgata, and L. woodi. T 8 is composed of two tergites broadly separated by membrane, in some species the tergites join at the posterior edge of the segment. In L. ibis, L. japuhybensis, L. purpurascens, and L. vulgata the posterior edge of the tergite is more or less connected by a narrow strip of cuticle. The shape of ST 8 is somewhat variable among species. The shape of the epiproct and hypoproct are similar between species though they exhibit some variation in shape (Figs. 135 – 158 )). The spermathecae of all 12 species are similar as well (Figs. 147 – 158).

Key to the Species of Neotropical Lucilia See Tables 1, 2 for a comparison of important key characters in each species.

Distribution. Some species have very limited distributions so range information can be used to narrow down species identity. For example, endemic species in the West Indies and Galápagos Islands are not found on the mainland. Luclia mexicana is known only from Mexico, Guatemala, and Honduras in the Neotropics while L. ibis is known only from the eastern slope of the Andes in Argentina, Bolivia, and Peru. When distribution data helps distinguish species, it is included in the key. DNA Analysis. Samples of specimens for selected species were submitted to the BOLD project at the University of Guelph in an effort to increase information needed to distinguish valid species. See details of this project under Methods. CO 1 barcodes were generated for 14 species of Neotropical Lucilia. See the barcode diagram showing the clusters of species analyzed (Fig. 161). Details of barcoding results, when available, are given under each species.